Synthese tetrasubstituierter Ethylene durch reduktive Kupplung von Ketonen mittels Titan(II)-salzen. Zur Anwendung der Methode
作者:Dieter LENOIR
DOI:10.1055/s-1977-24469
日期:——
‘High-Surface Sodium’ as a Reducing Agent for TiCl3
作者:Alois Fürstner、Günter Seidel
DOI:10.1055/s-1995-3854
日期:1995.1
Sodium deposited on inorganic supports such as Al2O3, TiO2 and NaCl (‘high-surface sodium’) is a cheap, readily prepared, nonpyrophoric reducing agent for TiCl3. The low-valent titanium thus obtained, after only 1 h reduction time, is well suited for McMurry coupling reactions, particularly of aromatic carbonyl compounds. It exhibits a previously unrivalled template effect for the cyclization of dicarbonyl compounds to (macrocyclic) cycloalkenes and is suitable for the reduction of N-acyl-2-aminobenzophenone derivatives to 2,3-disubstituted indoles. Even a 36-membered ring could be formed without recourse to high dilution techniques.